Power system

ABSTRACT

A power system the size of which does not become very large although the system uses secondary batteries, and in which the supply of DC power is not stopped at the time of charging the battery after the secondary battery is completely discharged, and an amplification system for audio using the power system. When no signal is inputted to an amplifier ( 1 ) for audio for a fixed period of time or longer, a control circuit ( 4 ) gives a connection switching signal (b) to a connection switching circuit ( 7 ) under a fixed condition, but, Whenever the signal (b) is given to the circuit ( 7 ), one of the secondary batteries ( 6 A and  6 B) is switched to the power source of the amplifier ( 1 ) from a state where the battery is charged by means of a charging circuit ( 8 ), and the other battery is switched to a state where the battery is charged by means of the circuit ( 8 ) from a state where the battery supplies electric power to the amplifier ( 1 ).

TECHNICAL FIELD

This invention relates to a power system or the like which supplies DCpower to an electronic appliance into which contamination of noises fromoutside should be avoided as much as possible as in an amplifier foraudio.

BACKGROUND ART

Conventionally, as a power system which supplies DC power to anelectronic appliance such as an amplifier for audio which dislikescontamination of noises from outside, there was used such a system that,after accepting the supply of alternate power, which would be rectified,obtained a power in the shape of rectified wave, and obtained a directcurrent with ripples as little as possible by means of a smoothingcapacitor, a ripple filter circuit, and a stabilizing circuit, etc., andoutputted this.

However, even if the above described power system was used, any DC powercompletely without ripples was not obtainable, and in the case when sucha DC power was supplied to the above described amplifier for audio,noise (hum) due to the ripples was generated by the amplifier for audio.

Taking the above described background into consideration, in recentyears, amplifiers for audio, etc., which are supplied with power frombatteries (that is secondary batteries) with huge capacities, have beenproposed, and some have already been introduced for practical use.

However, an amplifier for audio, etc., powered by a battery with a hugecapacity, which is large in size, is inconvenient in terms oftransportability and installation, and in addition when the battery isdischarged and the supply of power has been stopped, it will becomenecessary for the battery to be charged over a comparatively long hours,and during the period the amplifier for audio, and moreover, any audioequipment itself will not become unusable.

The present invention has been accomplished, by contemplating the abovedescribed backgrounds, and the purpose thereof is to provide a powersystem or the like which does not become very large in terms of size,and in addition does not halt any supply of DC power due to chargingafter discharge.

DISCLOSURE OF THE INVENTION

In a first invention, a power system to supply an electronic appliancewith a DC power is configured as follows. That is, such a configurationcomprises:

a plurality of secondary batteries;

a detecting circuit on absence of signal which detects whether or notthere is any input signal into the above described electronic appliance,and in the case when there is no above described input signalcontinuously for a predetermined fixed time period, sends out adetecting signal on absence of signal to indicate such a state;

a charging circuit which, after receiving the supply of an alternatepower, implements the supply of DC power for charging;

a connection switching circuit which connects one of a plurality of thesecondary batteries with the above described electronic appliance sothat the battery functions a secondary battery for the supply of powerto supply the electronic appliance with a DC power, and connects theothers with the above described charging circuit so as to function assecondary batteries to be charged, and every time when a detectingsignal on absence of a signal is sent out from the detecting circuit onabsence of a signal, switches connection status, and causes the onewhich functioned as the secondary battery for the supply of power up tothe point of time to function as the secondary battery to be charged,and causes one of those batteries which functioned the secondary batteryto be charged up to the point of time to function as the secondarybattery for the supply of power.

The above described configuration makes such a power system obtainablethat does not become very large in terms of sizes and in addition, forcharging the battery after the time when the secondary battery on dutyis completely discharged, will not halt the supply of DC power to theabove described electronic appliance.

In the second invention, a power system to supply an electronicappliance with a DC power is configured as follows. That is, such aconfiguration comprises:

a plurality of secondary batteries;

a detecting circuit on absence of signal which, after a predeterminedtime has lapsed since switching in connection status in thelater-described connection switching circuit has taken place, startsdetecting whether or not there is any input signal into the abovedescribed electronic appliance, and in the case when there is no abovedescribed input signal continuously for a predetermined fixed timeperiod, sends out a detecting signal on absence of signal to indicatesuch a state;

a charging circuit which, after receiving the supply of an alternatepower, implements the supply of DC power for charging; and

a connection switching circuit which connects one of a plurality of saidsecondary batteries with the above described electronic appliance sothat the battery functions a secondary battery for the supply of powerto supply the electronic appliance with a DC power, and connects theothers with the above described charging circuit so as to function assecondary batteries to be charged, and every time when a detectingsignal on absence of a signal is sent out from the detecting circuit onabsence of a signal, switches connection status, and causes the onewhich functioned as the secondary battery for the supply of power up tothe point of time to function as the secondary battery to be charged,and causes one of those batteries which functioned the secondary batteryto be charged up to the point of time to function as the secondarybattery for the supply of power.

The above described configuration makes such a power system obtainablethat does not become very large in terms of sizes, and in addition, forcharging the battery after the time when the secondary battery on dutyis completely discharged, will not halt the supply of DC power to theabove described electronic appliance.

In the third invention, a power system to supply an amplifier for audiowith a DC power is configured as follows.

That is, such a configuration comprises:

a plurality of secondary batteries;

a detecting circuit on absence of signal which, after a predeterminedtime has lapsed since switching in connection status in thelater-described connection switching circuit has taken place, startsdetecting whether or not there is any audio input signal into the abovedescribed amplifier for audio, and in the case when there is no theaudio input signal continuously for a predetermined fixed time period,sends out a detecting signal on absence of signal to indicate such astate;

a charging circuit which, after receiving an alternate power, implementsthe supply of DC power for charging; and

a connection switching circuit which connects one of a plurality of saidsecondary batteries with the above described amplifier for audio so thatthe battery functions a secondary battery for the supply of power tosupply the amplifier for audio with a DC power, and connects the otherswith the above described charging circuit so as to function as batteriesto be charged, and every time when a detecting signal on absence of asignal is sent out from the detecting circuit on absence of a signal,switches connection status, and causes the one which functioned as thesecondary battery for the supply of power up to the point of time tofunction as the secondary battery to be charged, and causes one of thosebatteries which functioned the secondary battery to be charged up to thepoint of time to function as the secondary battery for the supply ofpower.

The above described configuration makes such a power system obtainablethat does not become very large in terms of sizes, and in addition, forcharging the battery after the time when the secondary battery on dutyis completely discharged, will not halt the supply of DC power to theabove described amplifier for audio.

The fourth invention is configured so that the number of the secondarybattery in the power system in the above described first through thirdinventions is two.

In the fifth invention, an amplification system for audio has beenconfigured as follows.

That is, such a configuration comprises:

the power system according to the above described third invention;

an amplifier for audio which is provided with the power supply by saidpower system; and

a mute circuit to temporarily mute an output from the above describedamplifier for audio at the time when switching in connection status by aconnection switching circuit of the power system takes place.

Such a configuration serves to result in making obtainable not only theabove described effect due to usage of the above described power system,but also such an effect that any occurrence of uncomfortable switchingnoises from speakers originated in switching in connection status by theabove described connection switching circuit becomes avoidable.

The sixth invention is configured so that the number of the secondarybattery in the power system in the amplification system for audioaccording to the fifth invention is two.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit diagram showing a circuit configuration of apreferred power system of the present invention and an amplificationsystem for audio inclusive thereof in a built-in fashion, and

FIG. 2 is a time chart to describe an operation of this power system,etc.

BEST MODE FOR CARRYING OUT THE INVENTION

In order to explain and describe the present invention in furtherdetail, description hereon will be proceeded with reference to theattached drawings.

FIG. 1 is a circuit diagram showing a circuit configuration of apreferred power system of the present invention and an amplificationsystem for audio inclusive thereof in a built-in fashion. In thedrawing, an amplifier for audio 1 is an amplifier which receives anaudio signal as an input signal and amplifies this at a predeterminedamplifying ratio for outputting. A mute circuit 2 is at ordinary time, acircuit portion to which an output of the above described amplifier foraudio 1 is inputted, and which sends this to a circuit portion of thesubsequent step, and in addition, at the time when a mute instructionsignal “a” has been sent in from a driving signal generating circuit 5described later, mutes the above described input.

An attenuator 3 is a circuit portion to which the output from theamplifier for audio 1 is inputted, and which attenuates the levelthereof to a predetermined value and sends it out. A control circuit 4is a circuit portion to which the signal sent from the above describedattenuator 3 (that is, the one obtained by attenuating the output fromthe amplifier for audio 1) is inputted, and which, as of the time when apredetermined time period has lapsed subject to a switching operation ofa connection switching circuit 7 described later, looks into whether ornot the audio signal is included in the output of this amplifier foraudio 1, and if the audio electric signal is not included therecontinuously over a fixed time period, sends a signal to indicate such astate to the driving signal generating circuit 5. The driving signalgenerating circuit 5 is a circuit portion which receives the abovedescribed signal, and sends out a mute instructing signal “a” to themute circuit 2, and immediately afterwards sends a connection switchingsignal “b” to the connection switching circuit 7.

The connection switching circuit 7 is a circuit portion, which comprisesfour relays 7A, 7B, 7C, and 7D, and connects either secondary battery 6Aor 6B with a charging circuit 8 for charging and connects the otherthereof with the amplifier for audio 1 for implementing the supply of DCpower to the amplifier for audio 1 and, then receiving the connectionswitching signal “b” from the driving signal generating circuit 5,causes the party which has been supplying the amplifier for audio 1 witha power so far to undergo charging with the charging circuit 8, andcauses the party which has been undergoing charging with the chargingcircuit 8 so far to be connected with the amplifier for audio 1 so as tocause it to supply the amplifier for audio 1 with power. That is, eachtime the connection switching signal “b” is sent in, moving contacts ofthe above described respective relays switch from the state under whichthe moving contacts are respectively in contact with fixed contacts 7A1,7B1, 7C1, and 7D1 (the fixed contacts symbolized by black triangles inthe drawing) to the state under which the moving contacts arerespectively in contact with fixed contacts 7A2, 7B2, 7C2, and 7D2 (thefixed contacts symbolized by white triangles in the drawing), or inbackward direction from the state under which the moving contacts arerespectively in contact with fixed contacts 7A2, 7B2, 7C2, and 7D2 tothe state under which the moving contacts are respectively in contactwith fixed contacts 7A1, 7B1, 7C1, and 7D1. Incidentally, the movingcontacts of the relays 7A and 7B are respectively in contact with thepower terminal of the amplifier for audio land with the earth, and themoving contacts of the relays 7C and 7D are respectively in contact withthe positive and negative output terminals of the charging circuit 8.

The secondary batteries 6A and 6B have approximately the samecharging-discharging features, and compared with the batteries describedin the conventional example, are smaller in terms of capacity as well assize. The charging circuit 8 is a circuit portion to which an alternatepower is given and which performs its rectifying operation or the liketo send it out.

FIG. 2 is a time chart showing the operation of this power system aswell as amplification system for audio, and with reference to this FIG.2 and FIG. 1 already described, the operation of this power system aswell as amplification system for audio will be described as follows. Forexample, now, suppose in the connection switching circuit 7 the movingcontacts of the relays 7A and 7B are respectively in contact with thefixed contacts 7A2 and 7B2, and the moving contacts of the relays 7C and7D are respectively in contact with the fixed contacts 7C2 and 7D2, andconsequently the secondary battery 6B is supplying the amplifier foraudio 1 with power and the secondary battery 6A is in a state wherecharging with the charging circuit 8 is taking place. In addition, atthe point of time T_(a) shown in FIG. 2, if a connection switchingsignal “b” has been sent in from the driving signal generating circuit 5to the connection switching circuit 7, the respective moving contacts ofthe relays 7A, 7B, 7C, and 7D will come into contact with fixed contactsdifferent from the fixed contacts with which they used to be in contactuntil then, and as shown in FIGS. 2(B) and 2(C), the secondary battery6A will supply the amplifier for audio 1 with power, and the secondarybattery 6B will enter the state of undergoing charging.

For example, now, suppose the input signal to the amplifier for audio 1(equivalent to, that is, the signal to be given to the control circuit 4via the attenuator 3) is identical to that shown in FIG. 2(A). In thiscase, the control circuit 4 in FIG. 1 will not, as shown in FIG. 2(D),implement its detecting operation on whether or not any audio signal iscontained in the above described given signal, until such a point oftime T_(b) when a predetermined fixed time period t_(s) has lapsed.Accordingly, though in the case where the portion indicated with thecode NS, that is, the audio signal, in FIG. 2(A), does not appear for afixed time period of to, described later, or longer, the connectionswitching operation will not be implemented in the connection switchingcircuit 7. A time period required for completing charging the secondarybatteries 6A, 6B is set as the above described fixed time period t_(s).

After the point of time T_(b) when the above described fixed time periodt_(s) has lapsed, the above described control circuit 4 proceeds withchecking on whether or not the above described given signal contains anaudio signal, and in the case where the signal is absent for a fixedtime period to or longer as indicated by the code AS shown in FIG. 2(A),the circuit detects this and gives a signal expressing such a state tothe driving signal generating circuit 5. Incidentally, the abovedescribed fixed time period to is set up so that it is a little shorterthan the duration (generally a several seconds) of absence of sounds atthe time when, for example, a piece of music is being followed byanother piece of music in the case where a CD (Compact Disc) in which anumber of pieces of music are recorded is being replayed.

The driving signal generating circuit 5 to which the above describedsignal has been given by the control circuit 4 firstly sends out a muteinstructing signal “a” to the mute circuit 2, and immediately thereaftersends out a connection switching signal “b” to the connection switchingcircuit 7. The mute circuit 2 to which the mute instruction signal “a”has been given mutes the output from the amplifier for audio 1 for anextremely short time period t_(m) (see FIG. 2(E)), and during this timeperiod t_(m), the connection switching circuit 7 which has received theabove described connection switching signal “b” implements connectionswitching and restores the state prior to the point of time T_(a), andsupplies the amplifier for audio 1 with power from the secondary battery6B and starts charging the secondary battery 6A. And subsequently theabove described operation will be repeated. Thus, while one of secondarybatteries 6A and 6B is being used as a power for the amplifier for audio1, the other is arranged to undergo charging, and after this other partyhas undergone charging sufficiently, when any audio signal is absent fora fixed period of time or longer, the output from the amplifier foraudio 1 is muted for an extremely short period of time, during such aperiod the secondary battery which has been undergoing charging untilthen is placed on duty as a power for the amplifier for audio 1, and theother party battery starts undergoing charging, which switchingoperation will be repeated. Thus, no such a case will occur that theamplifying operation of the amplifier for audio 1 must be halted inorder to charge the secondary batteries 6A, 6B. Thus availability timeperiod of these two secondary batteries may be comparatively short, andaccordingly, the secondary batteries do not have to be large in terms ofcapacity, and moreover the one with smaller sizes will do.

INDUSTRIAL APPLICABILITY

As described in detail so far, the power system according to the firstthrough fourth inventions does not become very large in terms of sizesin spite of their using secondary batteries, and in addition, after thesecondary battery is completely discharged, the supply of DC power willnot be halted at the time of charging the battery. Thus, such a powersystem is useful for a power for electronic facilities which needs thecontinuous supply of a DC power.

In addition, in the amplification system for audio according to thefifth invention which the power system according to the above describedthird invention is built in as well as in the amplification system foraudio according to the sixth invention, not only the above describedeffect due to usage of the above described power system, but also suchan effect that any occurrence of uncomfortable switching noises fromspeakers originated in connection switching by a connection switchingcircuit inside the above described power system can become avoidable canbe obtained. Therefore, such an amplification system for audio is usefulas the amplifier for various audio appliances.

What is claimed is:
 1. A power system for supplying an electronicappliance with DC power characterized by comprising: a plurality ofsecondary batteries; a detecting circuit on absence of signal whichdetects whether or not there is any input signal into the abovedescribed electronic appliance, and in the case when there is noabove-described input signal continuously for a predetermined fixed timeperiod, sends out a detecting signal on absence of signal to indicatesuch a state; a charging circuit which, after receiving an alternatepower, implements the supply of DC power for charging; and a connectionswitching circuit which connects one of a plurality of said secondarybatteries with the above described electronic appliance so that thebattery functions a secondary battery for the supply of power to supplysaid electronic appliance with a DC power, and connects the others withthe above described charging circuit so as to function as secondarybatteries to be charged, and every time when a detecting signal onabsence of a signal is sent out from said detecting circuit on absenceof a signal, switches connection status, and causes the one whichfunctioned as said secondary battery for the supply of power up to thispoint of time to function as said secondary battery to be charged, andcauses one of those batteries which functioned said secondary battery tobe charged up to said point of time to function as said secondarybattery for the supply of power.
 2. A power system for supplying anelectronic appliance with a DC power characterized by comprising: aplurality of secondary batteries; a detecting circuit on absence ofsignal which, after a predetermined time has lapsed since switching inconnection status in the later-described connection switching circuithas taken place, starts detecting whether or not there is any inputsignal into the above described electronic appliance, and in the casewhen there is no above-described input signal continuously for apredetermined fixed time period, sends out a detecting signal on absenceof signal to indicate such a state; a charging circuit which, afterreceiving an alternate power, implements the supply of DC power forcharging; and a connection switching circuit which connects one of aplurality of said secondary batteries with the above describedelectronic appliance so that the battery functions a secondary batteryfor the supply of power to supply said electronic appliance with a DCpower, and connects the others with the above described charging circuitso as to function as secondary batteries to be charged, and every timewhen a detecting signal on absence of a signal is sent out from saiddetecting circuit on absence of a signal, switches connection status,and causes the one which functioned as said secondary battery for thesupply of power up to this point of time to function as said secondarybattery to be charged, and causes one of those batteries whichfunctioned said secondary battery to be charged up to said point of timeto function as said secondary battery for the supply of power.
 3. Apower system for supplying an amplifier for audio with DC powercharacterized by comprising: a plurality of secondary batteries; adetecting circuit on absence of signal which, after a predetermined timehas lapsed since switching in connection status in the later-describedconnection switching circuit has taken place, starts detecting whetheror not there is any audio input signal into the above describedamplifier for audio, and in the case when there is no said audio inputsignal continuously for a predetermined fixed time period, sends out adetecting signal on absence of signal to indicate such a state; acharging circuit which, after receiving an alternate power, implementsthe supply of DC power for charging; and a connection switching circuitwhich connects one of a plurality of said secondary batteries with theabove described amplifier for audio so that the battery functions asecondary battery for the supply of power to supply said amplifier foraudio with a DC power, and connects the others with the above describedcharging circuit so as to function as batteries to be charged, and everytime when a detecting signal on absence of a signal is sent out fromsaid detecting circuit on absence of a signal, switches connectionstatus, and causes the one which functioned as said secondary batteryfor the supply of power up to this point of time to function as saidsecondary battery to be charged, and causes one of those batteries whichfunctioned said secondary battery to be charged up to said point of timeto function as said secondary battery for the supply of power.
 4. Thepower system according to claim 1, wherein the number of said secondarybattery is two.
 5. An amplification system for audio characterized bycomprising: the power system according to claim 3; an amplifier foraudio which is provided with the power supply by said power system; anda mute circuit to temporarily mute an output from said amplifier foraudio at the time when switching in connection status by a connectionswitching circuit of said power system takes place.
 6. The amplificationsystem for audio according to claim 5, wherein the number of saidsecondary battery for said power system is two.